Department of Infectious Disease, College of Pharmaceutical Sciences, Matsuyama University, Japan.
Japan Aerospace Exploration Agency (JAXA), Ibaraki, Japan.
FEBS Lett. 2023 May;597(10):1345-1354. doi: 10.1002/1873-3468.14626. Epub 2023 Apr 27.
Sortase-mediated pili are flexible rod proteins composed of major and minor/tip pilins, playing important roles in the initial adhesion of bacterial cells to host tissues. The pilus shaft is formed by covalent polymerization of major pilins, and the minor/tip pilin is covalently attached to the tip of the shaft involved in adhesion to the host cell. The Gram-positive bacterium Clostridium perfringens has a major pilin, and a minor/tip pilin (CppB) with the collagen-binding motif. Here, we report X-ray structures of CppB collagen-binding domains, collagen-binding assays and mutagenesis analysis, demonstrating that CppB collagen-binding domains adopt an L-shaped structure in open form, and that a small β-sheet unique to CppB provides a scaffold for a favourable binding site for collagen peptide.
Sortase 介导的菌毛是由主要和次要/尖端菌毛组成的柔性杆状蛋白，在细菌细胞与宿主组织的初始黏附中发挥重要作用。菌毛轴由主要菌毛的共价聚合形成，而次要/尖端菌毛则共价连接到参与与宿主细胞黏附的轴的尖端。革兰氏阳性菌产气荚膜梭菌具有主要菌毛和具有胶原结合基序的次要/尖端菌毛（CppB）。在这里，我们报告了 CppB 胶原结合结构域的 X 射线结构、胶原结合测定和突变分析，证明 CppB 胶原结合结构域在开放形式下采用 L 形结构，而 CppB 特有的小 β 片层为胶原肽提供了有利的结合位点的支架。
